I am agree that feeding animation became better and maybe "darker", but visuals of skills feels darker? Maybe i didn't understand what you mean, but do you remember old visuals?
Also new Eviscerate looks like paint, bats in bat swarm ult now looks like they made of foil, Mesmorize have pink-purple colored visuals, more suited for Barbie doll. Don't feels darker, in my opinion.
Do you think the old visuals of vampire skills lacked identity and recognizability? How purple-pink colors illustrate power of the vampire skills and add vampiric atmosphere? And i think making almost all vampire skills using same color pattern is so lame, old visuals of vampire skills used unique color schemes and effects and were very vampiric and easily recognisable.
Some choices might feel a tad exaggerated, but give the user an identity in game among all classes and skills available: when in PvP I like to recognize what people are using, or what they are.
The form and choice of colors illustrate the powers of the skill one is executing well and add more to the atmosphere. I like it.
Just my 2 cents, opinions can differ ofcourse.